Roy Rossotti was the original director of "A Change of Mind", but after a few days, Patrick McGoohan replaced him under the pseudonym of Joseph Serf.
Like "It's Your Funeral", this episode is very studio based, and much of the actual Portmeirion footage is either stock, or uses doubles to represent the main actors.
The social group scene is evocative of the self-criticism that Chinese people had to undergo in Chairman Zedong Mao's regime. Notably an Asian prisoner accuses him of being "reactionary" (a left wing criticism), whereas another accuses him of being a "rebel" (possibly a right wing criticism). The term "unmutual" was also supposedly used during the Joseph McCarthyite witch hunts for one involved in "un-American activities". Thus this episode can be seen as criticising both far left and far right politics. The furious mob which picks up and humiliates No 6 is similar to the Cultural Revolution, which was in full swing when The Prisoner (1967) was written and produced.
Several contemporary regimes used psychiatry for political purposes, much like "A Change of Mind". Notably in the USSR, some dissidents were famously diagnosed with "sluggishly progressing schizophrenia", and given electro-convulsive therapy, surgery and medication, so that the Soviet government could claim that they were incarcerated for medical, rather than political reasons. The episode also ties in with the anti-psychiatry movement which emerged in the 1960s, with the likes of R.D. Laing and Thomas Szasz seeing psychiatry as a means of imposing social conformity, even in the West. The Doctor accuses No 6 of being suspicious, and No 42 accuses him of being aggressive, even though he is in a prison. A notable 1960s book parallel to this movement is the book by Ken Kesey which became One Flew Over the Cuckoo's Nest (1975).